Karyotypic analysis in mungbean (Vigna radiata (L) wilczek)

Karyotypic analysis in 10 morphologically diverse varieties of mungbean showed that all the varieties were diploid having 22 chromosomes in their somatic cells and their haploid number was 11. While individual chromosome length ranged from 1.20 to 2.35 mm, the total length of haploid set varied from 18.30 to 22.33 mm. Of the eleven basic chromosomes, two were found to have a secondary constriction with subterminal primary constriction and these fell in either long or in medium chromosome group. In respect of centromere position all the varieties had six metacentric and five submetacentric chromosomes, where the centromeric formula 5 sm + 6 m could be assigned. Detailed karyotypic characteristics differed slightly among the varieties. TF% varied from 40.04 to 41.45 indicating a high degree of karyotypic similarity among the varieties. All the varieties except Q10593 had 2A type of karyotype. On the other hand, Q10593 fell in 2B group. The low magnitude of difference in chromosome characteristics of the morphologically diverse varieties indicated that genetic processes such as mutation rather than chromosomal changes have played an important role in the intraspecific evolution of mungbean.